One of the important point in the Scrum approach is the fact that user stories are estimated using a relative size and not the “exact” man/days measure used to size effort by traditional project management approaches. In this blog post, Ilan Goldstein discusses how to explain the relative estimation concept in Scrum.
The relative estimation of user stories can be defined in story points that follow a Fibonacci sequence (1, 2, 3, 5, 8, 13, 20) or use clothing size (XS, S, M, …). The post explains that the relative estimation ...